Powder coating material such as powder paint is commonly applied to an object by spraying the powder coating material. Typically, a spray gun or material application device is used, and spray guns may be manually held and operated or automatic spray guns may be used that are controlled electronically. Spray technologies include for example electrostatic, non-electrostatic and tribo-electric. The powder flow path through a spray gun must be purged whenever the powder coating material, such as its color or other characteristic, is changed, in order to prevent unwanted contamination.